反应详情

温度

-78 °C

(S)-4-Benzyloxazolidin-2-one (35 g, 0.2 mol) was dissolved in THF (500 mL) and cooled to −78° C. A solution of nBuLi in hexane (80 mL, 0.2 mol) was added dropwise. The solution was stirred at this temperature for 30 min and then (E)-but-2-enoyl chloride (19 mL, 0.2 mol) was added slowly. The cold bath was removed and the reaction was allowed to stir at room temperature for 1 h, whereupon saturated NH4Cl solution (200 mL) was added. Most of the THF was removed under vacuum and the mixture was partitioned between ether and brine. After drying over Na2SO4, the organic layer was concentrated and the residue purified by silica gel chromatography (20% EtOAc in hexanes) to give the desired product (39 g, 79% yield) as a white solid.

1. customThe cold bath was removed
2. stirringto stir at room temperature for 1 h, whereupon saturated NH4Cl solution (200 mL)
3. additionwas added
4. customMost of the THF was removed under vacuum
5. customthe mixture was partitioned between ether and brine
6. dry with materialAfter drying over Na2SO4
7. concentrationthe organic layer was concentrated
8. customthe residue purified by silica gel chromatography (20% EtOAc in hexanes)